Strut bearings are part of the wheel suspension in independent wheel suspensions. The wheel suspension supports a desired driving safety and driving comfort, as well as easy and precise steering of the wheels. The wheel suspension should keep road surface noises from the vehicle body and should be as lightweight as possible. Depending on the design, the strut bearing guides the shock absorber spring and forms a support surface for the shock absorber end stop. The strut bearing absorbs the radial and axial forces transmitted via the shock absorber spring or to the shock absorber and ensures that the shock absorber spring rotates with little friction and no torsion and thus operates without a restoring moment.
Strut bearings are often part of the so-called MacPherson strut. The strut essentially is formed of the spring, shock absorber, and steering knuckle. The strut bearing is provided with a cap that is mounted on the chassis-side strut brace, as well as with a guide ring on which the shock absorber spring is supported and guided by this guide ring. The guide ring is mounted so that it can rotate relative to the cap. During steering, the bearing allows a rotation of the spring relative to the vehicle body, because the entire strut rotates during steering motions.
From DE 10 2010 015 712 A1, a strut bearing is known that has a cap and a guide ring that can rotate relative to the cap. Between the cap and guide ring there is a plain bearing. The plain bearing is formed from a sliding element that is arranged between the guide ring and the cap.
EP 2 317 167 A1 discloses a strut bearing with a cap, a guide ring, and a plain bearing arranged in-between. The plain bearing is inserted into a recess of the guide ring and forms a sliding surface for the cap.
DE 10 2008 057 590 A1 describes a strut bearing that has a cap and a guide ring. The cap and the guide ring are made from metal. Between the cap and the guide ring there is a plain bearing that is formed from a synthetic resin.